A152997 Twice 13-gonal numbers: a(n) = n*(11*n - 9).

0, 2, 26, 72, 140, 230, 342, 476, 632, 810, 1010, 1232, 1476, 1742, 2030, 2340, 2672, 3026, 3402, 3800, 4220, 4662, 5126, 5612, 6120, 6650, 7202, 7776, 8372, 8990, 9630, 10292, 10976, 11682, 12410, 13160, 13932, 14726, 15542, 16380, 17240, 18122, 19026, 19952, 20900, 21870, 22862, 23876

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

a(n) = 11*n^2 - 9*n = A051865(n)*2.

a(n) = a(n-1) + 22*n - 20 (with a(0)=0). - Vincenzo Librandi, Nov 27 2010

From G. C. Greubel, Sep 01 2019: (Start)

G.f.: 2*x*(1 + 10*x)/(1-x)^3.

E.g.f.: x*(2 + 11*x)*exp(x). (End)

Maple

seq(n*(11*n-9), n=0..50); # G. C. Greubel, Sep 01 2019

Mathematica

Table[n*(11*n-9), {n, 0, 50}] (* G. C. Greubel, Sep 01 2019 *)

Prog

(Magma) [n*(11*n-9): n in [0..50]];
(PARI) a(n)=n*(11*n-9) \\ Charles R Greathouse IV, Jun 17 2017
(Sage) [n*(11*n-9) for n in (0..50)] # G. C. Greubel, Sep 01 2019
(GAP) List([0..50], n-> n*(11*n-9)); # G. C. Greubel, Sep 01 2019

Crossrefs

Cf. A051865 (13-gonal numbers).

Cf. numbers of the form n*(n*k - k + 4))/2 listed in A226488 (this sequence is the case k=22). - Bruno Berselli, Jun 10 2013

Sequence in context: A132861 A210848 A247957 * A345693 A229573 A337396

Adjacent sequences: A152994 A152995 A152996 * A152998 A152999 A153000

Keyword

easy,nonn

Author

Omar E. Pol, Dec 22 2008

Extensions

Terms a(39) onward added by G. C. Greubel, Sep 01 2019

Status

approved